DESCRIPTION (Verbatim from the Applicant's Abstract): The project applies interferometric and geometric moire methods from geometrical and physical optics principles to x-ray imaging. One application of these methods can be used to obtain ultra-high resolution images with edge enhanced contrast via refractive-index imaging, with further contrast enhancement from x-ray extinction. A second related application can be used to identify tissue type with remarkable specificity. Further, such identification is independent of the x-ray geometric path length through the tissue, and is done by measuring and imaging the tissue-specific ratio of the total attenuation to the coherent small-angle deBye scattering production, that, in turn, sensitively depends on the average atomic number (relative compositions of carbon, oxygen, and higher Z atoms), and also on the average protein-folding length. Both schemes are non-invasive, in-vivo, require no contrast agent, have low dosage, and require only short duration exposures. Both are accomplished using polychromatic x-rays from a conventional medium power x-ray tube, and lead to low-cost clinically-practical devices. Proof-of-principle experiments for both schemes have now been successfully accomplished. PROPOSED COMMERCIAL APPLICATION: Not Available